Vitamin D metabolites in captivity? Should we measure free or total 25(OH)D to assess vitamin D status?

• Published in: The Journal of steroid biochemistry and molecular biology Vol. 173; pp. 105 - 116
• Main Authors: Bikle, Daniel, Bouillon, Roger, Thadhani, Ravi, Schoenmakers, Inez
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.10.2017
• Subjects: Animals; Centrifugal ultrafiltration; Free vitamin D metabolites; Genetic polymorphism; Humans; Immunoassay - methods; Keratinocytes; Liver disease; Polymorphism, Genetic; Pregnancy; Protein Binding; Ultrafiltration - methods; Vitamin D - analogs & derivatives; Vitamin D - blood; Vitamin D - metabolism; Vitamin D binding protein; Vitamin D Deficiency - blood; Vitamin D Deficiency - genetics; Vitamin D Deficiency - metabolism; Vitamin D-Binding Protein - genetics; Vitamin D-Binding Protein - metabolism; Vitamins - blood; Vitamins - metabolism; Pregnancy; Liver disease; Genetic polymorphism; Keratinocytes; Vitamin D binding protein; Centrifugal ultrafiltration; Free vitamin D metabolites

•Free 25(OH)D can be measured directly by a two step immunoassay, ultrafiltration or dialysis. All such assays need further validation.•Free 25(OH)D can also be calculated based on measurements of total vitamin D metabolites, DBP, albumin, and the affinities between the metabolite and the binding pr...